Hi, I have serveral stores, and what I do with customer's information is that I store them into each computer in each store. For example, Computer A, will only contain Store A's customer info, and Computer B will only contain Store B's customer info. What software or script will allow me to store Customer's info to a server(online). So as long as the computers have internet access, I can simiply go to a specific site(could be my site) http://www.mysite.com/customer/ to do the Data Entry online. Therefore I could easily access my customer's info from anywhere in the world, because All the information is on a server.
If you dont know how to program but you understand how data is stored (databases) you can use phpmyadmin to manage your data... maybe thats the simplest way... but I think youll need a management system.